The present invention relates to an improved hanger and seal suitable for use in conditions of wide variations in and extremes of temperature. The maintenance of a proper seal under such conditions of temperature variations has proven to be a problem. Such temperature conditions could be experienced in production in Alaska (-75.degree. F. to 250.degree. F.) and in steam injection applications (up to 650.degree. F.).
The use of elastomer seals has not been satisfactory for such temperature conditions because the elastomers are subject to breakdown and they have expansion and contraction rates which differ substantially from those rates of the mating metal parts. Temperature cycling has caused elastomers to break down so that they crack or lose desirable qualities such as shape and durometer hardness. Also, resilient seals are often adversely affected by well bore fluids.
Metal seals have been used and even though they may be inert to well bore fluids they have been subject to problems by virtue of being distorted or crushed by differential expansion of the parts to such an extent as to fail to seal when reversal of the temperature results in contraction of the parts. Most metal seals are compression seals and do not have any provision to limit crushing of the seal ring due to differential expansion and contraction of the mating parts resulting from temperature variances.